Today's high speed optical network systems use optical fiber connectors to connect optical fiber ends together. These connectors have highly polished endfaces that are required to meet certain industry standards for performance and intermateability. One standard, Telcordia GR326-CORE issue 3, states that optical fiber connectors must meet defined specifications for the following three parameters of endface geometry: radius of curvature, fiber undercut, and apex offset. Consistent endface geometry creates an optimal core-to-core alignment during the mating process of two connectors.
Orbital polishers are known that repeat a spiral pattern around a central drive axis, such as the pattern shown in FIG. 4. FIG. 4 shows orbital rotation about a rotational axis A of the polishing disk, which is also referred to herein as a polishing wheel, plate and/or platen, together with rotation about another drive axis B that creates a circular-spiral pattern between the polishing surface and a fiber end held in contact with the polishing surface of the orbital polisher. A polishing disk may refer to a replaceable single unit or may be comprised of a plurality of components, such as a durable platen and a disposable disk having a polishing surface. Orbital polishers are known to create wear of the polishing surface along circular paths. Thus, polishing disks must often be replaced due to wear or build-up of foreign particles locally in a high-wear area on the disk. Also, the orbital pattern of such polishers is not as efficient as the pattern that may be applied by a highly skilled human polishing a fiber end by hand. Also, series of polishing media and pressures are used to achieve polished fiber ends that meet industry standards, but this process either requires multiple polishing disks or time consuming replacement of polishing surfaces between one polishing medium and the next in the series. These shortcomings increase costs and reduce portability of polishing stations. For example, U.S. Pat. No. 4,979,334 discloses an orbital polishing apparatus having a polishing disc rotating about its own axis with the entire disc rotating about another drive axis.
State of the art polishing methods require multiple steps, such as five separate steps, requiring five minutes of polishing to meet industry standards for optical fiber end face geometry. For example, polishing may require epoxy removal (30 seconds), radius forming (90 seconds), rough polishing (60 seconds), final polishing (60 seconds), and finishing polishing (60 seconds), this is an inefficient and impractical process when applied in the field and outside of a controlled plant environment.
Optical fiber polishers using the current optical fiber polishing technology have the additional problem of having to apply varying amounts of pressure between the connector end and the polishing surface for each of the five polishing steps. These pressures are complex to set up and to maintain throughout the polishing process. Applying too much or too little pressure during a polishing step may adversely affect the quality of the polished connector end surface. For example, U.S. Pat. No. 6,077,154 discloses an optical fiber polishing apparatus that reduces burdens on operators for adjusting polishing pressure between steps of polishing, but fails to eliminate the need for adjusting polishing pressure between polishing steps.
While previous inventions provided orbital patterns and improved adjustability of the apparatus, an improved polishing pattern that provides for an apparatus capable of a one-step process for fiber end polishing would be a compelling improvement over the state of the art orbital polishers. If such a polisher were portable and capable of long use on a single charge of a battery, then it would be more readily adapted for use in the field than systems requiring mounting in a van and comparatively high power consumption.